Filter assemblies and valves for filter assemblies

ABSTRACT

A filter assembly may include a valve which includes a valve member and a sleeve. The valve member moves between a first position and a second position in response to rotation of the sleeve.

This application is a divisional of U.S. application Ser. No.10/694,404, which was filed on Oct. 28, 2003, and is a continuation ofU.S. application Ser. No. 09/462,765, which is now abandoned and was theUnited States national phase of International Application No.PCT/GB98/01975, which was filed on Jul. 6, 1998, all of which areincorporated by reference.

The invention relates to filter assemblies and valves.

A known form of filter assembly comprises a housing providing an inletport and an outlet port with a filter element being held in the housingand comprising a filter medium having a central passage extendingbetween first and second ends of the filter medium. The first end of thefilter medium is connected to an end cap to close the passage and thesecond end of the filter medium is in fluid communication with a port ofthe housing.

In this way, fluid passing to the housing flows through the filtermedium in a path including the inlet port, the outlet port and thepassage. Such filters are used extensively for medical, biomedical andpharmaceutical purposes.

It is a requirement of such filter assemblies that the filter elementmust be capable of being integrity tested. For water-wettable filtermedia integrity can be tested by the Water Bubble Point Test or theDiffusive Forward Flow Test. In the Water Bubble Point Test, the filterelement is placed in a water bath with both the first and second ends ofthe passage closed and air is pumped into the passage at a pressurewhich is increased until the first bubble is observed on the exterior ofthe filter medium. If the structure of the filter medium has integrityover its whole volume, this first bubble will appear at a predeterminedpressure. If a bubble or bubbles appear at a lower pressure, it is anindication that the structure of the filter medium is not uniform overthe whole volume of the filter medium. This can indicate the incidenceof passages through the filter medium which might allow the passagethrough the medium in use of unfiltered or only partly filtered fluid.

In the Diffusive Forward Flow Test, the filter medium is wetted withwater and surplus water is removed. Air is applied to one side of themedium at a specified pressure and the diffusive air flow rate ismeasured. This diffusive air flow rate has been found to be related tothe removal rating of the medium. A greater than expected flow rate canindicate lack of integrity of the medium.

However, the connection to a water-wettable filter medium of an end capcan change the characteristics of the medium so that integrity testingis no longer possible. For example, the connection can producehydrophobic zones in the medium which do not wet out in the integritytest and thus plainly affect the performance of the medium in theintegrity test.

For this reason, the materials of the filter medium and the end cap areusually chosen so that connection of the medium and the end cap does notaffect the characteristics of the medium in a manner that would affectthe medium's performance in an integrity test.

The material of the end cap is also important for hydrophobic filtermedia. Some hydrophobic filter media are easily damaged by heat. Thesemedia are attached to the end cap by heating the end cap to soften theend cap and inserting the first end of the medium into the end cap whilethe end cap is softened. It is therefore important to choose a materialfor the end cap that softens at a relatively low temperature such thatthe connection can be carried out without damaging the media.

However, it is also a requirement for such filter assemblies that havemedical, biomedical and pharmaceutical uses that they can be sterilizedto allow for repeated use. There are two principal forms ofsterilization; in situ steam sterilization and steam autoclaving. Insitu steam sterilization, instead of fluid to be filtered passing to thefilter assembly, high pressure and high temperature steam are passedthrough the filter assembly. For example, the steam pressure may beseveral bars and the temperature 140° C. In steam autoclaving, thefilter assembly is removed from associated equipment and transferred toan autoclave where it is steam sterilized. The filter assembly is thenremoved from the autoclave, transferred aseptically and replaced in theequipment. A typical filter assembly might need sterilizing 100 times inits lifetime.

Where the housing of such a filter assembly is made of a plasticsmaterial, the second end of the filter medium is usually connected tothe housing by heating the housing material and inserting the second endof the filter medium into the housing material. For water-wettablemedia, in order to produce a water wettable joint for integrity testingpurposes, it is thus necessary to have the housing of an appropriatematerial that produces the required join. For hydrophobic media that arerelatively easily damaged by heat it is necessary for the plasticsmaterial of the housing to have a relatively low softening temperature.Such plastics materials are not able to withstand the pressures andtemperatures of in situ steam sterilization. Accordingly, such filterassemblies must be sterilized by autoclaving. This requires the filterassembly to be removed from service, autoclaved and then transferredaseptically back into service.

The known alternative is to house the filter element in a metal housing.The metal will withstand the temperatures and pressures of in situ steamsterilization but metal housings are typically much bulkier thanplastics housings and are more expensive to produce and require cleaningbefore re-use.

It is also a problem with filter assemblies in providing valves for theinlet port and the outlet port. Such valves need to be capable of steamsterilization, and many are not.

According to a first aspect of the invention, filter assemblies maycomprise a plastics housing, a filter element, a passage, and a valve.The housing has an interior, an exterior, an inlet port, and an outletport. The filter element is in the interior of the housing and includesa filter medium. The passage extends between the interior and theexterior of the housing. The valve includes a valve member and arotatable sleeve. The valve member is located within the passage and ismovable between a first position and a second position. In the firstposition, fluid flow along the passage is permitted. In the secondposition, the valve member seals the passage and fluid flow along thepassage is prevented. The valve member moves axially between the firstand second positions in response to rotation of the sleeve.

According to a second aspect of the invention, filter assemblies maycomprise a plastics housing, a filter element, a passage, and a valve.The housing has an interior, an exterior, an inlet port, and an outletport. The filter element is in the interior of the housing and includesa filter medium. The passage extends between the interior and theexterior of the housing and has a first portion and a second portion.The valve includes a rotatable sleeve, a pin, a slot, and a valvemember. The valve member moves between a first position and a secondposition. In the first position, the valve member is in the firstportion of the passage and the valve is open. In the second position,the valve member is sealed within the second portion of the passage andthe valve is closed. The valve member moves axially in the passage inresponse to rotation of the sleeve and engagement of the pin in theslot.

According to a third aspect of the invention, valves for filterassemblies may comprise a passage member, a sleeve member, and a valvemember. The sleeve member surrounds the passage member. The valve memberhas a passage and extends into the passage member from an end of thepassage member. One member includes a pin and another member includes aco-operating slot. Rotation of the sleeve member results in axialmovement of the valve member between a first position and a secondposition. In the first position the valve member opens the passagemember for fluid connection with the passage in the valve member, and inthe second position the valve member closes the passage member.

The following is a more detailed description of an embodiment of theinvention, by way of example, reference being made to the accompanyingdrawings in which:

FIG. 1 is an exploded view of a filter assembly showing first and secondparts of a filter housing, a filter element within the housing andvalves connected to inlet and drainage ports of the housing,

FIG. 2 is a cross-section on the axis of the housing of FIG. 1, showingone valve in an open position and a second valve in a closed position,

FIG. 3 is detail B of FIG. 2 showing the open valve to a larger scale,and

FIG. 4 is detail C of FIG. 2 showing the closed valve to a larger scale.

Referring to the drawings, and particularly FIG. 1, the filter assemblycomprises a housing indicated generally at 10, a filter element 11encapsulated in the housing 10 and two valves 12 carried by the housing10.

The housing 10 comprises a first housing part 13 and a second housingpart 14. Both parts are made, for example moulded, from a polysulphonematerial. The first housing part 13 includes an end wall 15 providedwith an inlet port 16 for the medium to be filtered, and a circularcross-section side wall 17 extending downwardly from the end wall 15 andterminating at a circular edge 18. An outwardly facing annular rebate 19is formed in the side wall 17 adjacent the edge.

An air vent port 20 is formed at the junction between the end wall 15and the side wall 17 and extends in a direction generally radiallyrelative to the axis 21 (see FIG. 2) of the housing 10. The innersurface 60 of the air vent port 20 defines a passage having a smallerdiameter portion 22 closer to the side wall 17 and a larger diameterportion 23 further from the side wall 17 and terminating at the end ofthe air vent port 20. Five ribs 61 extend into the larger diameterportion 23 from the inner surface 60. The ribs 61 are spacedequi-angularly around the surface 60. Each rib 61 has an edge 62 that iscontinuous and in line with the inner surface 60 at the small diameterportion of the passage.

The air vent port 20 has an exterior surface 24 provided with an annulargroove 25 adjacent the end of the port 20 which carries an O-ring seal26. In addition, this surface 24 has two pins 27 projecting radiallyfrom the surface at respective positions on the surface spaced from theend of the port 20. The function of the seal 26 and the pins 27 isdescribed below.

The second housing part 14 includes a second end wall 28 provided with adisc-shaped stand 29. The second end wall 28 has its end remote from thestand of generally annular shape coaxial with the axis 21 of the housing10. This portion of the second end wall 28 is provided with an inwardlyfacing rebate 30.

As best seen in FIG. 2, the second end wall 28 has an outlet port 31 inthe form of a generally circular cross-section passage co-axial with theaxis 21 of the housing 10 and extending through the second end wall 28and the stand 29. The end of the outlet port 31 within the housing 10forms an annular flange 32.

A drainage port 33 is provided in the second end wall 28 and extendsradially from the second end wall 28 relative to the axis 21 of thehousing 10. The drainage port 33 is constructed similarly to the airvent port 20 (parts common to the two ports 20,33 are given the samereference numerals and will not be described in detail).

The filter element 11 comprises a filter medium 34, a first end cap 35,a second end cap 36 and a cage 37. The filter medium may be of anyconvenient material and any convenient shape that provides a centralpassage for the flow of fluid to be filtered. For example, the filtermedium 34 may be annular. The material may be pleated or unpleated.Examples of suitable filter media are those sold by Pall Corporationunder the trademarks ULTIPOR, FLUORODYNE, SUPOR and EMFLON.

The filter medium 34 has a first end and a second end with the passageextending between the ends. The first end cap 35 is disc-shaped and isformed from a plastics material. The first end cap 35 is preferablyconnected to the first end of the filter medium 34 by heating the endcap 35 to soften the end cap 35 and then inserting the filter mediuminto the softened end cap material to form a join.

The material of the first end cap 35 is chosen so that, when the filtermedium 34 is connected to the first end cap 35, the characteristics ofthe medium 34 are not materially changed. In particular, when the filtermedium 34 is of a water-wettable material, the material of the first endcap is chosen to that a water wettable joint is formed between thefilter medium 34 and the first end cap 35. In this case, the end capmaterial will depend on the material of the filter medium 34. Forexample, when the filter medium 34 is a FLUORODYNE or SUPOR medium, theend cap 35 maybe composed of polypropylene. When the filter medium 34 iscomposed of a nylon material the first end cap 35 may be composed of apolyester or nylon material.

It is important to obtain a water-wettable joint between water-wettablefilter media and the first end cap 35 in order to allow the filterelement to be integrity tested. An integrity test involves the filterelement being placed in a bath of water (with the ends of the passageclosed) and air is then supplied to the passage at increasing pressure.The bath is then observed to determine at what pressure the first bubbleappears on the exterior of the filter medium. If the porous structure ofthe filter medium is integral over the whole area of the filter medium,then the first bubble will appear at a relatively high pressure. If,however, the porous structure is not integral over the whole area of thefilter medium 34, then the first bubble will appear at a relativelylower pressure. If the junction between the first end cap 35 and thefilter medium 34 is not water-wettable, it creates a hydrophobic zonethrough which air passes readily since the porous structure is notwetted out by water. Although this does not normally affect filtrationduring use of the assembly, it is not possible to test the integrity asdescribed above. The formation of hydrophobic zones similarly preventsthe medium being tested by the Diffusive Forward Flow Test describedabove.

Where the filter medium 34 is hydrophobic, it is important to ensurethat the first end cap 35 is composed of a material that can be softenedat a temperature that is sufficiently low so that the integrity of themedium 35 is not damaged by the insertion process. For example, when thefilter medium 34 is composed of PVDF (such as an EMFLON 2 medium) thefirst end cap 35 may be composed of polypropylene. Where the filtermedium 35 is composed of PTFE, which is relatively resistant to heat, itis also preferable to use polypropylene end caps.

The second end cap 36 comprises a flat annular portion 38 with a centralaperture. A projecting tube 39 surrounds the aperture and extends awayfrom the filter medium 34 in a direction normal to the plane of the flatannular portion 38. The tube 39 is provided with two annular seals 40 onits exterior surface 41. Four flanges 42 project radially outwardly ofthe flat annular portion 38 and are equi-angularly spaced around thisportion 38.

The outer diameter of the tube 39 is generally equal to the interiordiameter of the outlet port 31.

For any filter medium 34, the material of the second end cap is chosenbased on the same considerations affecting the choice of the material ofthe first end cap. The material of the second end cap 36 will normally,but not necessarily, be the same as the material of the first end cap35. The filter medium 34 is connected to the second end cap 36 byheating the second end cap 36 and then inserting the filter medium 34into the softened material. The cage 37, which is of known type,surrounds the exterior surface of the filter medium 34 between the firstand second end caps 35,36.

The filter element 11 is mounted in the housing in the following way.First, the tube 39 on the second end cap 36 is inserted into the outletport 31 in the second end wall 28. The seals 40 prevent leakage betweenthese parts. When fully inserted, the flange 32 of the outlet port 31bears against the under-surface of the flat annular portion 38 of thesecond end cap 36. This holds the filter element 11 in the second endwall 28 coaxial with the housing axis 21. In addition, it connects theinterior passage of the filter medium 34 with the outlet port 31 via thetube 39.

The first housing part 13 is then placed over the filter element 11 withthe edge 18 fitting within the second end wall 28 and the rebate 19adjacent this edge mating with the rebate 30 in the second end wall 28.The first and second housing parts 13,14 are then welded together aroundthe rebates 19,30.

When so positioned, the edge 18 of the side wall 17 bears against theflanges 42. The effect of this is to clamp the filter element 11 betweenthis edge 18 and the end of the flange 32 surrounding the outlet port 31and contacting the second end cap 36. In this way, the filter element 11is held firmly in position encapsulated in the housing 10.

Referring next to FIGS. 3 and 4 in particular, the valves 12 controlflow through the air vent port 20 and the drainage port 33. The valves12 are identical and so only one of them will be described.

The valve 12 comprises an elongated valve member 43 which is generallycircular in cross-section. The valve member 43 has a blind end 44 withinthe associated port. The blind end 44 carries an O-ring 45 in a grooveprovided on an exterior surface. The remainder of the valve member 43has an axial passage 46 leading to a connector 47 for connection to ahose or pipe. In FIG. 3 the connector 47 has an annulartriangular-section rib 63 and in FIG. 4 the connector 47 has asuccession of axially spaced ribs 64. At least one radial passage 48connects the end of the axial passage 46 adjacent the blind end 44 withthe exterior surface of the valve member 43.

A sleeve 49 is arranged coaxially with the axis of the valve member 43and is spaced from the valve member 43 by an annular radially extendingflange 50. The sleeve 49 is a sliding fit over the exterior surface 24of the associated port 20,31. In addition, the sleeve is provided withtwo helical slots 51 (seen best in FIG. 1) extending around a portion ofthe sleeve 49. Each pin 27 is received in a respective one of the slots51.

The sleeve 49 can thus be rotated relative to the associated port 20,33with such rotation being controlled by the engagement of the pin 27 inthe slot 51 to cause the sleeve 49 also to move axially relative to theassociated port 20,33. This rotation can take place in both senses.

The effect of this rotation is best seen in FIGS. 3 and 4. At one limitof rotation in one sense, as seen in FIG. 3, the blind end 44 of thevalve member 43 lies in the larger diameter portion 23 of the associatedport 20,33. When so positioned, the valve member 43, and the associatedO-ring 45, do not obstruct the port and so allow flow into the port,through the radial passage 48 and along the axial passage 46. Reverseflow is, of course, also possible. Leakage around the sleeve 49 isprevented by the O-ring seal 26 on the exterior surface 24 of the port20,33. The O-ring 45 is kept pressed into the groove on the outersurface of the blind end by the ribs 61—the edges 62 bearing against theO-ring 45.

Rotation of the sleeve 49 in the opposite sense moves the blind end 44into the smaller diameter portion. The O-ring 45 is guided into thesmaller diameter portion by the edges 62. Maximum rotation in theopposite sense disposes the valve member as shown in FIG. 4. In thisdisposition, the blind end 44 lies within the smaller diameter portion22 of the associated port 20,33. The O-ring 45 seals against the innersurface 60 of the port 20, 33 so preventing flow through the value. Itwill be appreciated that because the seal is made against thecircumference of the smaller portion 22 (and not, for example, against aradially extending seat) the port 20, 33 and the valve member 43 canundergo differential expansion during heating without causing damage tothe valve as the blind end 44 simply moves axially with the smallportion 22.

Thus, by twisting the sleeve 49 is one sense or the other, theassociated port 20, 33 can be opening or closed. It will also beappreciated that the pin 27 and slot 51 mechanism prevents the valve 12being disengaged completely from the associated port 20, 33.

The valves 12 are preferably made from a polysulphone material.

The housing parts 13, 14 and the valves 12 may also be made from anyother suitable plastics material capable of withstanding in-linesterilization. As stated above, in-line sterilization involves passingsteam under pressure through the housing. The exterior of the housing iskept at atmospheric pressure and so there is a pressure differentialacross the housing. The minimum temperature and pressure of steamcommonly used for sterilization is generally about 121° C. at about 1bar above atmospheric pressure, although in some circumstances, inparticular if exposure to the steam is prolonged, sterilization may beachievable at lower temperatures and pressures. However, it is oftendesirable to sterilize the assembly in-line under harsher conditions,for example using steam at about 142° C. and about 2.83 bar aboveatmospheric pressure. The housing is preferably resistant to suchharsher conditions. Examples of plastics other than polysulphone thatare suitable are PEEK, PEK, polyphenyleneoxide, polyphenylenesulphide,polyethersulphone polyalkoxysulphone and polyarylsulphone.

In use, the filter assembly described above with reference to thedrawings is mounted in a line containing a fluid to be filtered. Thismay be, for example, a medical, biomedical or pharmaceutical fluid. Atube leading from a source of fluid to be filtered is connected to theinlet 16. The outlet port 31 is connected to a receiver of filteredfluid. The drainage port 33 is connected to a tube leading to a receiverfor drained fluid. The valve 12 of the air vent port 20 is opened andthe valve 12 of the drainage port 33 is closed. Fluid to be filtered isthen fed through the inlet 16 to fill the housing 10. The air vent port20 is then shut. The fluid passes through the filter medium 34 where itis filtered and the filtered fluid enters the passage before passingthrough the tube 39 and the outlet port 31.

When the filter assembly is to be sterilized, the inlet 16 isdisconnected from the supply of fluid to be filtered and the outlet port31 is disconnected from the receiver of filtered fluid. The drainageport valve 12 is open to drain excess fluid from the housing 10. Theinlet 16 is then connected to a supply of steam under pressure and theoutlet port 31 is connected to a drain. The valves 12 are left slightlyopen. Steam at the pressure of several bars and a temperature of about140° C. is then fed through the housing to steam sterilize the filtermaterial 34 and the other components. The housing 10, since it is madeof polysulphone (or another suitable plastics material), is able towithstand the temperature and pressure of the steam. The same is true ofthe valves 12; because they are made of polysulphone (or anothersuitable plastics material), they will withstand the in-line steamsterilization without damage.

Once steam sterilization is complete, water can be drained by fullyopening the drainage port valve 12 and the filter assembly reconnectedfor filtering fluid.

By separating the caps 35,35 from the housing 10, these parts can bemade in different materials to provide the water wettability necessaryfor the filter medium 34 and the resistance to in-line steamsterilization necessary for the housing 10.

It will be appreciated that there are a number of modifications that canbe made to the arrangement described above.

The valves 12 need not be as described above. Any suitable valves couldbe used. The plastics material of the housing 10 need not bepolysulphone, it could be any material that is capable of withstandingin-line steam sterilization. The filter element 11 need not be clampedin the housing 10 as described, it could be held in any suitable way.The cage 37 need not be as described, any suitable cage could beprovided. The filter medium 34 may be provided with upstream and/ordownstream drainage layers.

1. A filter assembly comprising: a plastics housing having an interior,an exterior, an inlet port, and an outlet port; a filter element in theinterior of the housing and including a filter medium; a passageextending between the interior and the exterior of the housing; and avalve including a valve member and a rotatable sleeve, wherein the valvemember is located within the passage and is movable between a firstposition in which fluid flow along the passage is permitted and a secondposition in which the valve member seals the passage and fluid flowalong the passage is prevented and wherein the valve member movesaxially between the first and second positions in response to rotationof the sleeve.
 2. The filter assembly of claim 1 wherein the valveincludes a pin and a slot which receives the pin, the engagement of thepin in the slot causing the valve member to move axially between thefirst and second positions in response to rotation of the sleeve.
 3. Thefilter assembly of claim 2 wherein the slot is in the sleeve.
 4. Thefilter assembly of claim 1 wherein the passage includes first and secondportions, the valve member sealing the second portion in the secondposition.
 5. The filter assembly of claim 4 wherein the second portionof the passage has a smaller diameter than the first portion.
 6. Thefilter assembly of claim 4 wherein the passage includes a third portionwhich extends through the valve member, the first portion and the thirdportion of the passage fluidly communicating in the first position. 7.The filter assembly of claim 4 wherein the first portion of the passageincludes a plurality of spaced ribs.
 8. The filter assembly of claim 1wherein the valve member is connected to the sleeve and the sleeve movesaxially with the valve member.
 9. A filter assembly comprising: aplastics housing having an interior, an exterior, an inlet port and anoutlet port; a filter element in the interior of the housing andincluding a filter medium; a passage which extends between the interiorand the exterior of the housing, the passage having a first portion anda second portion; and a valve including a rotatable sleeve, a pin, aslot, and a valve member, wherein the valve member moves between a firstposition in which the valve member is in the first portion of thepassage and the valve is open and a second position in which the valvemember is sealed within the second portion of the passage and the valveis closed, and wherein the valve member moves axially in the passage inresponse to rotation of the sleeve and engagement of the pin in theslot.
 10. The filter assembly of claim 9 wherein the pin and the slotare arranged with the sleeve and the housing to move the valve memberaxially in response to rotation of the sleeve and engagement of the pinin the slot.
 11. The filter assembly of claim 9 wherein the slot is inthe sleeve.
 12. The filter assembly of claim 9 wherein the valve memberis connected to the sleeve.
 13. The filter assembly of claim 9 whereinthe slot is in the sleeve, the pin is on the housing, and the valvemember is connected to the sleeve and wherein the sleeve and the valvemember move axially in response to rotation of the sleeve and engagementof the pin in the slot.
 14. The filter assembly of claim 9 wherein thepassage includes a third portion which extends through the valve memberand wherein the third portion and the first portion of the passagefluidly communicate in the first position.
 15. The filter assembly ofclaim 9 wherein the valve member includes a blind end and wherein theblind end of the valve member is sealed within the second portion of thepassage in the second position.
 16. The filter assembly of claim 9wherein the first portion of the passage includes a plurality of ribs.17. The filter assembly of claim 9 wherein the pin and the slot arearranged with the sleeve and the housing, the valve member is connectedto the sleeve, the valve member includes a blind end which is sealedwithin the second portion of the passage in the second position, and thepassage includes a third portion which extends through the valve member,the third portion and the first portion of the passage fluidlycommunicating in the first position.
 18. The filter assembly of claim 9wherein the second portion of the passage has a smaller diameter thanthe first portion.
 19. A valve for a filter assembly comprising apassage member, a sleeve member surrounding the passage member, and avalve member having a passage and extending in to the passage memberfrom an end thereof, one member including a pin and another memberincluding a co-operating slot such that rotation of the sleeve memberresults in axial movement of the valve member between a first positionin which the valve member opens the passage member for fluid connectionwith the passage in the valve member and a second position in which thevalve member closes the passage member.
 20. A valve according to claim19 wherein the pin is carried on an exterior surface of the passagemember and the slot extends helically partially around the sleevemember.
 21. A valve according to claim 19 wherein, in the secondposition, the valve member sits in and seals against a circumference ofthe passage member, closing the passage member, and, in the firstposition, the valve member does not seal against the circumference ofthe passage member, opening the passage member.
 22. A valve according toclaim 19 wherein the passage member includes a larger diameter portionand a smaller diameter portion, the valve member closing the smallerdiameter portion in the second position thereof.
 23. A valve accordingto claim 22 wherein the valve member includes a blind end, the blind endentering the smaller diameter portion in the second position to closethe passage member.
 24. A valve according to claim 22 wherein the valvemember carries a seal which seals against the smaller diameter portionin the second position.
 25. A valve according to claim 22 wherein thevalve member lies within the larger diameter portion in the firstposition.
 26. A valve according to claim 22 wherein the larger diameterportion includes a plurality of ribs within said passage member, theribs guiding the seal into the smaller diameter portion as the valvemember moves to the second position.
 27. A valve according to claim 26wherein the valve member carries a seal and the seal includes an O-ringcarried in a groove on the valve member and wherein the ribs keep theO-ring in the groove when the valve member is in the first position. 28.A valve according to claim 19 wherein the valve member includes a blindend and wherein the valve member passage includes an axially extendingportion leading to a connector and a radially extending portionconnecting the axial portion to an exterior surface of the valve memberspaced from the blind end.
 29. A valve according to claim 19 wherein thesleeve member surrounds an exterior surface of the passage member and aseal is provided between the sleeve member and the exterior surface ofthe passage member.
 30. A valve according to claim 29 wherein the sealincludes an O-ring carried in a groove on the exterior surface of thesleeve member.
 31. A valve according to claim 19 wherein the sleevemember is connected to the valve member.